Star formation in globular clusters and dwarf galaxies and implications for the early evolution of galaxiesBased upon the observed properties of globular clusters and dwarf galaxies in the Local Group, we present important theoretical constraints on star formation in these systems. These constraints indicate that protoglobular cluster clouds had long dormant periods and a brief epoch of violent star formation. Collisions between protocluster clouds triggered fragmentation into individual stars. Most protocluster clouds dispersed into the Galactic halo during the star formation epoch. In contrast, the large spread in stellar metallicity in dwarf galaxies suggests that star formation in their pregenitors was self-regulated: we propose the protocluster clouds formed from thermal instability in the protogalactic clouds and show that a population of massive stars is needed to provide sufficient UV flux to prevent the collapsing protogalactic clouds from fragmenting into individual stars. Based upon these constraints, we propose a unified scenario to describe the early epochs of star formation in the Galactic halo as well as the thick and thin components of the Galactic disk.
Lin, Douglas N. C. (Lick Observatory Santa Cruz, CA, United States)
Murray, Stephen D. (Leander McCormick Observatory Charlottesville, VA, United States)
August 16, 2013
January 1, 1991
Publication: In: The formation and evolution of star clusters (A93-48676 20-90)